Evolving a novel red-emitting two-photon dye with optically tunable amino group for monitoring the degree of hypoxia during liver fibrosis

Tandem reaction-powered near-infrared fluorescent molecular reporter for real-time imaging of lung diseases

Diabetes and its complications have drawn growing research attention due to their detrimental effects on human health. Although optical probes have been used to help understand many aspects of diabetes, the lung diseases caused by diabetes remain unclear and have rarely been explored. Herein, a tandem-reaction (TR) strategy is proposed based on the adjacent diol esterification-crosslinking reaction and the nicotinamide reduction reaction of nicotinamide adenine dinucleotide (NADH) to design a lung-targeting near-infrared (NIR) small molecule probe (NBON) for accurate imaging of diabetic lung diseases. NBON was designed by coupling a phenylboronic acid analog that can form borate ester bonds by reversibly binding with NADH via an esterification-crosslinking reaction. Streptozotocin (STZ)-induced diabetic mice and metformin (MET)/epalrestat (EPS)-repaired model studies demonstrated that NBON allowed the sensitive imaging of NADH for lung disease diagnosis and therapeutic monitoring. The proposed antioxidant mechanism by which EPS alleviates diabetic lung disease was studied for the first time in living cells and in vivo. Furthermore, NBON was successfully applied in the detection of NADH in tumors and lung metastases. Overall, this work provides a general platform for a NIR NADH probe design, and advances the development of NADH probes for mechanistic studies in lung diseases.

A Simple Methoxyquinoline-Based Ratiometric Fluorescent Probe for Specific Detection of Hydrogen Peroxide in Living Cells and Zebrafish

A simple methoxyquinoline-based ratiometric fluorescent probe was synthesized for detecting hydrogen peroxide (H2O2). After the probe reacted with H2O2, 6-methoxyquinoline fluorescence dye was released, and the fluorescence intensity increased at 366 nm and decreased at 450 nm. And the fluorescence ratio of the probe at 366 and 450 nm is linearly related to the concentration of H2O2 in the range of 0-100 μM; it shows a good ratiometric fluorescence signal. In addition, the probe has good characteristics such as rapid response speed and high sensitivity and selectivity. This fluorescent probe with low biotoxicity and excellent cell membrane permeability was further used to image H2O2 in HeLa cells and zebrafish.

A Cascade Activation Probe with Double-Enhanced Near-Infrared Imaging for Monitoring Peroxynitrite Fluctuations in Vivo

Monitoring peroxynitrite (ONOO-) fluctuations is particularly important for assessing pathological progression and oxidative damage due to their crucial role in maintaining the redox balance of organisms. However, due to the lack of efficient tools for differentially monitoring ONOO- fluctuations at different concentration ranges in vivo, the precise detection of endogenous ONOO- fluctuations under pathological conditions in living systems remains challenging. Herein, we rationally designed a double-enhanced emission cascade activatable near-infrared (NIR) fluorescent probe (B-TCF) for the measurement of ONOO-, which consists of a borate ester response group and a malononitrile hemicyanine fluorophore. Especially, after sequential oxidative hydrolysis of the borate ester group and xanthene skeleton, B-TCF exhibited a sequentially double-enhanced NIR emission response at 776 and 625 nm for different ONOO- concentration ranges. Moreover, B-TCF revealed excellent and promising performance for ONOO- in terms of high selectivity, sensitivity, and reaction rate (k = 28.2 M-1 s-1). Motivated by the two-step emission signal enhancement and large wavelength shift in the NIR region, B-TCF enabled discriminative imaging of ONOO- with the low and high concentrations in living cells. Importantly, B-TCF was successfully applied for assessing the pathological progression of isoniazid and acetaminophen-induced liver damage in vivo by detecting the endogenous different ONOO- levels. Overall, this study not only demonstrates the first double-enhanced emission cascade activatable NIR fluorescent probe for measuring the dynamic variation of ONOO- in related diseases but also shows great potential as an effective molecular tool for evaluating the various stages of drug-induced liver damage.

Triphenylphosphine-bonded coumaranone dyes realize dual color imaging of mitochondria and nucleoli

Probing intracellular organelles with fluorescent dyes offers opportunities to understand the structures and functions of these cellular compartments, which is attracting increasing interests. Normally, the design principle varies for different organelle targets as they possess distinct structural and functional profiles against each other. Therefore, developing a probe with dual intracellular targets is of great challenge. In this work, a new sort of donor-π-bridge-acceptor (D-π-A) type coumaranone dyes (CMO-1/2/3/4) have been prepared. Four fluorescent probes (TPP@CMO-1/2/3/4) were then synthesized by linking these coumaranone dyes with an amphiphilic cation triphenylphosphonium (TPP). Interestingly, both TPP@CMO-1 and TPP@CMO-2 exhibited dual color emission upon targeting to two different organelles, respectively. The green emission is well localized in mitochondria, while, the red emission realizes nucleoli imaging. RNA is the target of TPP@CMOs, which was confirmed by spectroscopic analysis and computational calculation. More importantly, the number and morphology changes of nucleoli under drug stress have been successfully evaluated using TPP@CMO-1.

Metal-organic framework (MOF)-based materials for pyroptosis-mediated cancer therapy

Pyroptosis is regarded as a promising strategy to modulate tumor immune microenvironments for anticancer therapy. Although pyroptosis inducers have been extensively explored in the biomedical field, their drug resistance, off-targeting capacity, and adverse effects do not fulfill the growing demands of therapy. Nowadays, metal-organic frameworks (MOFs) with unique structures and facile synthesis/functionalization characteristics have shown great potential in anticancer therapy. The flexible choices of metal ions and ligands endow MOFs with inherent anti-cancer efficiency, whereas the porous structures in MOFs make them ideal vehicles for delivering various chemodrug-based pyroptosis inducers. In this review, we provide the latest advances in MOF-based materials to evoke pyroptosis and give a brief but comprehensive review of the different types of MOFs for pyroptosis-mediated cancer therapy. Finally, we also discuss the current challenges of MOF-based pyroptosis inducers and their future prospects in this field.

Liver fibrosis: pathological features, clinical treatment and application of therapeutic nanoagents

Liver fibrosis is a reversible damage-repair response, the pathological features of which mainly include damage to hepatocytes, sinusoid capillarization, hepatic stellate cells activation, excessive accumulation of extracellular matrix and inflammatory response. Although some treatments (including drugs and stem cell therapy) for these pathological features have been shown to be effective, more clinical trials are needed to confirm their effectiveness. In recent years, nanomaterials-based therapies have emerged as an innovative and promising alternative to traditional drugs, being explored for the treatment of liver fibrosis diseases. Natural nanomaterials (including extracellular vesicles) and synthetic nanomaterials (including inorganic nanomaterials and organic nanomaterials) are developed to facilitate drug targeting delivery and combination therapy. In this review, the pathological features of liver fibrosis and the current anti-fibrosis drugs in clinical trials are briefly introduced, followed by a detailed introduction of the therapeutic nanoagents for the precise delivery of anti-fibrosis drugs. Finally, the future development trend in this field is discussed.

Sensitive fluorescent detection of o-aminophenol by hemicyanine boronic acid

O-Aminophenol (OAP) is widely used in various industries, but it can have severe negative impacts on both the environment and human health. Herein, we reported the development of hemicyanine boronic acid (HBA) for the fluorescent detection of OAP. The reaction of HBA with OAP produced a strong fluorescence emission at 675 nm because of the generation of tricyclic borate ester hemicyanine (TBEH). The detection was very rapid, sensitive and specific. The detection had a linear range 0.1 - 10.0 µM in ethanol with a detection limit of 60 nM in water and ethanol. The accuracy and precision of our results were successfully verified via HPLC analysis. Our study offers a valuable tool for the facile and efficient detection of OAP, with practical applications in environmental and health management.